1. Field of the Invention
The subject invention generally pertains to electronic power conversion circuits, and, more specifically, to high frequency, switched mode electronic power converters. The subject matter relates to new isolated power converters which achieve higher efficiency compared to prior art power converters.
2. Description of Related Art
Often a power conversion circuit such as a ZVS flyback converter, as illustrated in FIG. 1, is used to convert power efficiently at high switching frequencies. The efficiency advantage of the ZVS Flyback converter relates to its relative simplicity and its ability to achieve zero voltage switching over a broad range of line and load. One disadvantage of the ZVS flyback is that it transfers net energy from its primary circuit to its secondary circuit only during the off time of the main primary switch, M1. Bidirectional ZVS flyback converters, such as FIG. 21 of U.S. Pat. No. 5,402,329 exist that can transfer energy to the secondary circuit during both states of the main switch. But, the net or average energy transferred from the primary circuit to the secondary circuit during the on time of the main switch is zero in the bidirectional flyback converter and in all flyback converters. In other words, there is no net energy transferred to the secondary circuit in a flyback converter during the on time of the main switch. The amount of energy transferred to the secondary circuit during the on time of the main switch in a bidirectional flyback converter is equal to the energy transferred from the secondary to the primary during the on time of the main switch. The coupled inductor boost converter is a topology that delivers net energy to the secondary circuit during both on state and off state of the main switch. The average current in the secondary circuit of a coupled inductor boost is lower than the average current in a flyback since the current flows during both operating states of the converter in a coupled inductor boost. Also, the voltage stress applied to secondary windings and secondary switches is lower in the coupled inductor boost converter giving the coupled inductor boost converter further advantages over the flyback. What is needed is a coupled inductor boost topology with zero voltage switching and an electromagnetic compatibility advantage.